Resumen

Polarization mode dispersion (PMD) is worldwide a major obstacle in the successful implementation of next-generation optical-fibre telecommunication networks. Countrywide PMD measurement results are presented which illustrate the extent of the PMD problem in the South African network. An analysis of these results highlights the urgent need for a suitable intervention strategy such as PMD compensation if the South African network is to operate extensively at 10 Gb/s and beyond. The effectiveness of a number of established PMD compensation techniques is demonstrated experimentally using PMD compensators which we built and tested. Furthermore, investigations into the stability of PMD in deployed fibre networks under local conditions illustrate how PMD gradually drifts in buried fibre, and rapidly fluctuates in aerial fibre. These results confirm that PMD compensation is extremely difficult in aerial fibre due to the need to track the rapid PMD fluctuations continuously in real-time. We also briefly discuss possible alternative strategies besides PMD compensation for dealing with the PMD problem in the South African network.